The atmospheric aerosol is a multi-phase system formed by atmosphere as well as solid and liquid particles suspending therein. It is a mixture consisting of molecular groups and liquid or solid particles suspending in the air and having certain stability, a small sedimentation rate, and a size ranging from one micrometer to dozens of micrometers. Aerosol particles mainly originate from artificial sources such as industrial activities, biological burning and the like, as well as natural sources such as dusts, offshore marine particles and the like.
Research shows that the atmospheric aerosol not only affects radiation balance of an earth surface layer system, but also causes the earth-atmosphere system to cool by adjusting a reflectivity of an earth atmosphere system through scattering solar shortwave radiation. It also causes a heating process through absorbing the solar radiation, and changes microphysical properties of clouds by affecting the microphysical process of formation of the clouds. Aerosol also significantly influences atmospheric chemical processes and biogeochemical cycle. At the same time, the aerosol particles contain some particles harmful to human body, which may cause serious problem to the health of human beings, especially in heavily populated urban areas with many industries. Therefore, retrieval of the atmospheric aerosol has a significant meaning to research of global climate change as well as monitoring and management of atmospheric pollution.
Currently, researchers home and abroad have made quite some achievements in terms of aerosol remote sensing retrieval. They also pay much attention to monitoring of the aerosol in designing novel sensors. However, most of the conventional retrieval algorithms are directed to large-size aerosol having average properties, and quite limited in terms of applications. For example, such algorithms are only adapted to dark ground surface. At present, there is no effective aerosol retrieval algorithm adapted to bright ground surface areas such as cities.